Synthesis and Photovoltaic Properties of Polymers Based on Cyclopentadithiophene and Benzimidazole Units

Bulletin of the Korean chemical society

Il Kim¹  Seijung Park¹  Youngeup Jin¹  Joo Young Shim¹  Suhee Song¹  Kwanghee Lee¹  Sung Heum Park¹  Hongsuk Suh¹  Sooncheol Kwon¹ 

关键词: Polymer;    Photovoltaic cells;    Synthesis;    Dimethyl-2H-benzimidazole;   

DOI  :  

学科分类：化学（综合）

来源: Korean Chemical Society

【 摘 要 】

The new semiconducting copolymers with 4,4-dialkyl-4H-cyclopenta[2,1-b:3,4-b`]dithiophene and 2,2-dimethyl- 2H-benzimidazole units were synthesized. The fused aromatic rings, such as cyclopentadithiophene (CPDT) unit, can make the polymer backbone more rigid and coplanar, which induces long conjugation length, narrow band gap, and strong intermolecular π-π interaction. The stacking ability was controlled through attaching of linear or branched alkyl side chains. The spectra of PEHCPDTMBI and PHCPDTMBI in the solid films show absorption bands with maximum peaks at 401, 759 and 407, 768 nm, and the absorption onsets at 925 and 954 nm, corresponding to band gaps of 1.34 and 1.30 eV, respectively. The devices comprising PHCPDTMBI with TiOX showed a VOC of 0.39 V, a JSC of 1.14 mA/cm2, and a FF of 0.34, giving a power conversion efficiency of 0.15%. The PHCPDTMBI with linear alkyl chain on CPDT shows good solubility in organic solvent with higher PCE value than that of PEHCPDTMBI.

【 授权许可】

Unknown